Meaning of the Sanskrit Word: jyotisam

  jyotisam—of all luminaries    Bg 10.21
  jyotisam—in all luminous objects    Bg 13.18
  jyotisam—by luminaries    SB 4.9.20-21
  jyotisam—of luminaries    SB 4.12.39
  jyotisam—of the luminaries    SB 5.16.1
  jyotisam—of the sun and other luminaries    SB 6.1.4-5
  jyotisam—of the luminaries like the sun and moon    SB 6.12.33
  jyotisam—of all the luminaries    SB 9.5.3
  jyotisam—knowledge of astrology (along with other aspects of culture in human society, and specifically in civilized society, there must be knowledge of astrology)    SB 10.8.5

Can't find any compound Sanskrit words containing jyotisam.